Prepare the crust: Preheat the oven to 325°F (163°C). Grease and line the bottom of a 9-inch springform pan with parchment paper. In a medium bowl, combine the graham cracker crumbs, sugar, melted butter, and cinnamon. Stir until the mixture resembles wet sand. Press evenly into the pan and bake for 8-10 minutes. Set aside to cool.

1. Prepare the filling: Beat the softened cream cheese with sugar and vanilla extract until smooth. Add eggs one at a time, mixing after each addition. Stir in sour cream, heavy cream, flour, and salt until fully combined. Pour the batter over the cooled crust and smooth the top.
2. Bake the cheesecake: Bake for 50-60 minutes or until the edges are set and the center is slightly jiggly when shaken. Turn off the oven, crack the door slightly, and let the cheesecake cool for 1 hour. Afterward, remove, cool at room temperature, then refrigerate for 4 hours or overnight.
3. Prepare the pecan topping: Combine corn syrup, brown sugar, butter, vanilla extract, and heavy cream in a saucepan. Cook over medium heat until smooth. Add pecans and stir to coat. Cook for an additional 3-4 minutes. Remove from heat and let cool slightly.
4. Assemble and serve: Once the cheesecake has chilled, pour the pecan topping over the cheesecake. Spread evenly and garnish with whipped cream or extra pecans if desired. Slice and serve chilled.